I am here to describe a certain issue I faced recently. Me and My friends are having a pet project called Wibrant(earlier named winbook). Which is a social media website, hosted here. It has a Django-react stack both repos can be found here, and is hosted on an EC2 instance of free tier, on AWS, which is associated to an elastic IP.
The backend is running on a docker container, on the server itself, however, we decided to host the frontend on vercel, which was initally hosted here. But I decided to proxy it using nginx. Nginx conf for both react and django can be found here
This configuration was working perfectly, until one night I was suddenly getting a 502 error on https://winbook.d3m0n1k.engineer/. Upon inspecting the nginx logs, I found an error like
no live upstreams while connecting to upstream
which I was unable to understand. So, I tried to curl the site, using my localhost and the server. I was able to curl it using my local system, but was not able to do the same with the ec2 server. I got the error:
curl: (35) error:0A000126:SSL routines::unexpected eof while reading
Upon researching I found this error to occur due to openssl version mismatch, so i tried to update it, but couldn't. So decided to spin up a new ec2 instance. I was able to curl the site from there. Thinking that fixed the issue, I migrated the whole set up to that instance and reassociated my elastic ip to that instance. I tried to test it, Only to find that it stopped working. Confused, I ran the curl command again, and it was failing too. On using a python script with requests module to get the site, I got this error from my latest setup.
Caused by SSLError(SSLZeroReturnError(6, 'TLS/SSL connection has been closed
However, now the previous setup started to work perfectly fine. So, I could curl the Vercel deployment when I didn't had the elastic IP associated to my instance, but couldn't if I did.
So, I figured it was some issue with the elastic IP. I suspected Vercel had blacklisted my IP maybe. So I reset the whole dns config of my domain, created and associated a new elastic IP with the instance, and it worked perfectly.
So, my question is..
- Has anyone faced such an issue before? If yes, what was the fix in your case.
- Is it really possible that Vercel has the IP in a blacklist of sorts?
This issue is probably non reproducible, but if someone find this thread, dealing with the same problem, I hope that the post and/or the comments/answers lead you to your solution. Cheers.
